Sullivan stressed that it was not like his sister to leave without telling anyone. Miller's daughter recently celebrated her birthday and it's not like her to miss an important event like that, he said.

Sullivan said he was grateful for everyone who helped search for his sister. Despite the cold weather, a crowd of nearly 75 people searched for Miller.

"We've assembled our friends and family to see if we can find her," Sullivan said outside the Tinicum Township Police Department before the search began. "We don't really know anything and if anyone can help us we'd appreciate it."

Sullivan, who was accompanied by their mother, Debra Grindle, said it was unusual for Miller to leave and not tell anyone where she was going.

Edmiston said the search included wooded areas in the township such as the John Heinz National Wildlife Refuge.

"We have no reason to believe there was foul play," Edmiston said. "We're just eliminating some factors. We're not sure where she went."

Sullivan described his sister as being about 5 feet 7 inches tall with a medium build. She has brown hair and brown eyes.

Miller, who attends a trade school in King of Prussia, was last seen at her home in the Essington section of the township on Nov. 17. No one has been able to reach her on her cellphone, according to police.

Miller's friends and neighbors described her as a sweet, caring person.

Jeanmarie Poff said her daughter is a friend of Miller's daughter. Poff said Miller was always involved in her daughter's life.

Kim Yezuita graduated from Interboro High School with Miller in 1991.

"We stick together," she said about the Interboro graduates' close bond.

"(Miller) was sweet to everyone," Yezuita said. "She never caused any waves."

Lori Connolly, another friend who graduated from Interboro with Miller, echoed Yezuita's comments.

"She always had a smile on her face," Connolly said.

Edmiston urged anyone with information about Miller's whereabouts to call the Tinicum Police Department at 610-521-3830 or dial 911.

Edmiston said investigators have no leads about Miller's whereabouts. He said investigators will continue to follow up on information today.

Edmiston reiterated that investigators do not have any reason to suspect foul play.